Most patients with a partial response (PR) on a computed tomography (CT) scan and a complete metabolic response (CMR) on a fluorodeoxyglucose (FDG)-positron emission tomography (PET) scan should be considered to have achieved complete response and at low risk for relapse of melanoma, according to study findings published in the Journal of the European Academy of Dermatology and Venerology.
In patients with metastatic melanoma, treatment with anti-PD1 immune checkpoint inhibitor has produced sustainable clinical activity. Nevertheless, strong predictive factors for long-term outcomes and relapse risk remain to be identified. The study was designed to compare FDG-PET imaging to CT scans for distinguishing absence of tumor vs residual tumors in patients with metastatic melanoma treated with anti‐PD1 immunotherapy between October 2014 and October 2017. All 26 patients (15 men and 11 women) were considered to be in complete remission; had CT scans and FDG-PET imaging performed within 2 months of immunotherapy treatment discontinuation; and had measurable and well-identified targets on imaging scans. Data on demographics, treatment, disease features, and outcomes were obtained from medical records.